spark git commit: [SPARK-17122][SQL] support drop current database

Repository: spark Updated Branches: refs/heads/master d24e73647 -> 96cc1b567 [SPARK-17122][SQL] support drop current database ## What changes were proposed in this pull request? In Spark 1.6 and earlier, we can drop the database we are using. In Spark 2.0, native implementation prevent us fr

spark git commit: [SPARK-17122][SQL] support drop current database

Repository: spark Updated Branches: refs/heads/branch-2.1 965c964c2 -> c4c5328f2 [SPARK-17122][SQL] support drop current database ## What changes were proposed in this pull request? In Spark 1.6 and earlier, we can drop the database we are using. In Spark 2.0, native implementation prevent u